Pump.



N. MOCARTY.

PUMP.

v APPLICATION IILBD JUNE 14, 1909.

Patented Feb. 21, 1911.

IIHHI h.

Ninn sTATgEs PATENT einen.

NORMAN MCCARTY, OF INDIANAPOLIS, INDIANA, ASSIGNOR TO ATLAS ENGINEWORKS,

OF INDIANAPOLIS, INDIANA, A CORPORATION 0F INDIANA.

PUMP.

Speciflcation of Letters Patent. Patented Feb. 21, 1911.

, Application filed J'une 14, 1909. Serial No. 502,041.

' To all whom it may concer/nf:

Be it known that I, NORMAN MCCARTY, a citizen of the United States,residing at Indianapolis, in the county of Marion and State of Indiana,have invented certain new and useful Improvements in Pumps, of which thefollowing is a specification.

In the operation of internal combustion engines of the non-explosivetype the fuel is introduced into the combustion chamber in measuredquantities which should be accurately measured in -accordance with theimmediate needs of the engine, in order to maintain auniform speed. Insuch engines the fuel is introduced into the combustion chamber at atime when there is a very considerable pressure therein and means mustbe provided for forcing the measured quantities of fuel through theatomizer into the combustion chamber.

The object of my present invention is to provide a governed pumpinmechanism, for the` purpose described, 1n which the governing mechanism,by means of which the measuringimechanism is controlled, will besubjected only to comparatively small pressures-so as not to interferewith the delicacy of movement of the controlling speed-con'- trolledgovernor, the fuel nevertheless being positively delivered by the pumpto the eng1ne.

The accompanying drawings illustrate my lnvention.

. Figure 1 is an elevation, in partial section,

of a pumpmechanism embodying my invenion nd Fig, 2 a section on line 2 2of In the drawings, 10 indicates the main body of the pump having formedtherein a measuring chamber 11 and a delivery chamber 12which areconnected by a passage 13. A valve 14A is arranged between the measuringchamber and the delivery chamber and opens toward the delivery chamber.Valve 14 may be of lany desired type, although in practice I deem itpreferable to make said valve of the springclyosed type, providing asuitable sprlng 15 for that purpose. In the form shown, the stem ofvalve 14 is extended through a nozzle member-17 arranged within the mainbody of the pump and held in place by means of a cap 18 within vwhich acylindrical bore 19 is formed to receive a guide head 20 which fits bore19 and is carried by the end of the stem of valve 14, the guide head 20being recessed as shown to receive -plunger relative to the' chamber 11may be variably compensated by the movement of the compensating plunger,the arrangement being such that, when the main plunger moves to decreasethe containing volume of the measuring chamber 11, the compensatingplunve'r will move in the opposite direction relative to the measuringchamber so as to increase the containing volume thereof, said increase'being more or less depending upon therelative movement of thecompensating plunger.l 1

In the present form, plungers 24 and 26 are connected by a lever 3lwhich is provided with a fulcrum 32. This fulcrum 32 is movable relativetothe lever 31 so as to vary the relative lengths of its two arms andsaid fulcrumis also mounted in a slot or guideway 33 formed in asuitable sup-.

porting bracket 34. Fulcrum 32 is also 'connected to, or carried by, anarm 35 which,

inturn, is carried by an eccentric strap 36 mounted upon an eccentric 37carried by a rock shaft 38, which is connected in any suitable manner toa speed controlled governor 39, so that a movement of the speedcontrolled governor due to variation in speed of rotation thereof willswing the eccentric 37 and thus shift fulcrum 32'relative to lever 31.

Projected into the discharging chamber 12, through a suitable packinggland 41, is a discharging plunger 42 which needs to be moved insynchronism with the other plungers, and leading from the dischargingchamber 12 is a discharge pipe 43, said pipe leading to the atomizer(not shown) of the I lever 31, so that movement of plunger 24 to producea vacuum in chamber 12 and con- 'terial pressures within chamber 11 andno engine, and having therein an outwardly opening check valve 44.

Any suitable means may be used for driving the several 'plungers and inthe present drawings I have shown a shaft 45 suitably geared to theengine. Upon this shaft is an eccentric 46 carrying a strap 47 providedwith an arm 48 connected at 49 to a lever 50. The plunger 42 isconnected at 43 with lever 50, and also connected to said lever is a.link 52 which is connected at 53 with plunger 24.

The operation 'is as follows :-VVith 'the parts in the position shown inthe drawings, fulcrum 32 is equidistant from the ends of into chamber 11will cause an equal movement of plunger 26 out of chamber 11, andconsequently the two plungers being of the same displacing value, therewill be no madischarge therefrom. By swinging eccentric 37 downward,fulcrum 32 will be thrown to the right, thus shortening the right-handarm,4 of lever 13 and .lengthening the left-hand arm, so that themovement of the compensating plunger 26 will be less than the movementof the plunger 24 and, when plunger 24 is driven into chamber 11, avolume of oil will be driven Jfrom chamber 11 outward past' valve 14,against the action-of spring 15, the said amount being accuratelydetermined by the difference in movement of the two plungers. Underthese conditions the only. pressure which will be exerted upon thefulcrum32 cannot exceed the strength of spring 15 which, as will beseen, need not materiallyexceed the vacuum producible within chamber 12.The 4 oil,which is discharged past valve 14, will be driven over intochamber 12 at a time when piston 42 is being withdrawn therefrom. On thesubsequent instroke of plunger 42, the amount of oil previouslydelivered into the chamber 12 will be driven out through pipe 43 againstany pressure which may eX- ist in said pipe, but this pressure cannot inany way reach the plungers 24 and 26 and therefore cannot in any wayaect the delicacy of operation ofV the speed-controlled governor.

It will be seen that, in the form shown, the plunger42 having a fixedstroke, and the check valve 41 preventing anyl back low into chamber 12from pipe-43, there will be a tendency for plunger` 42, on itsoutstroke,

sequently the spring 15 (or other means by which valve 14 is held closedduring the discharging action of plunger 42) needs be only suiicient instrength to prevent an opening of the valve 14 except as a result of thedischarging action of plunger 24. It is true' that the spring 15 might.be omitted, but in that case the valve 14 would be apt to be somewhaterratic in action and consequently the measuring action of the apparatuswould not be as accurate and uniform as is really desirable. v A

I claim as my invention:

1. In a pump comprising a measuring chamber, a discharge chamber and anintermediate connection between said chambers, an eject-ing plungercoperating with thev measuring chamber, a compensatlng plunger alsocoperating with the measuring cham-f ber, means for reciprocating thetwo plungers in opposite directions relative to the chamber whereby themovement of one will compensate the movement` of the other," adischarging plunger arranged to coperate' with the discharge chamber,and a valve arranged between the measuring chamber and the dischargingchamber.

2. In a pump comprising -a measuring chamber, a discharge chamber and anintermediate connection between said chambers, an ejecting plungercoperating with the measuring chamber, a compensating plunger alsocoperating with the measuring chamber, means for reciprocating the twoplungers in opposite directions relative to the chamber whereby themovement of one will compensate the movement of the-other, means forvariably .controlling the relative movement of the two plungers, a.discharging plunger arranged to coperate with the discharge chamber, avalve Aarranged between the measuring chamber andthe discharging chamberand means for'closing said valve during the discharge movement of theplunger in the discharge chamber.

3. In a pump comprising a measuring chamber, a discharge chamber, and anintermediate connection between said chambers, a valve arranged in saidpassage, a plunger projectable into the measuring chamber, acompensating plunger also projectable into the measuring chamber, alever connecting said two plungers for opposite movement relative to themeasuring chamber, a fulcrum for said lever, means for shifting saidfulcrum relative to the lever to vary theratio of the arms thereof, adischarge plunger mounted in the discharge chamber, and means fordriving. saidw plungers.

4. In a pump .comprising a measuringchamber, a discharge chamber, and anintermediate connection between said chambers, a valve arranged in saidpassage, means for holding said valve closed during discharge from thedischarge chamber, a plunger projectable into the measuring chamber, acomf `pensating plunger also projectable into the measuring chamber, alever connecting said two `plungers for opposite movement relative tothemeasurlng chamber, a fulcrum for said lever, means for shifting saidfulelfum relativ?1 to tlfle lefer ltio vary 1the ratio of h sand ninehundred and nine.

in Avthe discharge ehamelgp ang means for NOB-MAN MCCARTY l [L"S]driving said plunger. v Witnesses: f l' In Witness whereof, I havehereunto set ARTHUR M. Hoon,

my hand and seal at Indianapolis, Indiana, v THOMAS W. MCMEANS.

this fourth day of June, A. D. one thou-

